Asskjnob to westing



R. E. HELLMUND.

SYSTEM OF CONTROL.

APPLICATION FILED 001L113. 1918.

Patented June 15, 1920.

FI/J'Z F j- Z mound F Swirche: a' b c' o 'f' ASH/H2 b o o C O O 5 d 0 O 7E e o o f f o o y D O R36/62 9 7 R2 3/ L5 Fig 4.

WETNESSES: Fly 5 1 INVENTOR flJMd/Yfi l Rudo/f E. He/lmund mm M ATTOiRNEY UNITED STATES I BUDOLI E. 'HELLMUND, OF SWISSVALE, PENNSYLVANIA, ASSIGNOB 'IO WEB'IING- PATENT OFFICE.

HOUSE ELECTRIC MANUFACTUBING COMPANY, A CORPORATION 01' PENN- BYLVARIL.

1,343,211. Original applicition flied October,

legheny and State of Pennsylvania, ave in-- vented, a new and useful Improvement in Systems of Control, of which the following a plication being a is a specification, this 7 rial No. 127,381,

division of application filed October 24, 1916, patented Oct. 28,

My invention relates to systems of control for dynamo-electric machines, and it has special relation to theregenerative control 7 of electric motor'sthat are adapted for use in propelling electric railway vehicles and the like.

One object of my invention is to provide simple, durable and reliable means for eftecting regenerative operation of the momentum-driven armatures of motors of the above-indicated character, whereby a certain proportion of the energy absorbed during the propelling periodis returned to the supply circuit, to reduce operatin expenses, and whereby various other wellown operating advantages are secured.

Another object of my invention is to 'rovide a system of regenerative control w ich shall embody means for automatically compensating for the unavoidable voltage fluctuations in the supply-circuit voltage, whereby a substantially constant regenerated current is maintained duringsuch fluctuations.

More specifically stated, an objetzt of my invention is to provide a motor-' enerator set or dynamotor of relativel sma l capacity for variably energizing t e main series field magnet winding of the propelling motor or motors during regenerative operation. The set maybe driven either from the regenerative circuit or from a suitable exter-. nal source of energy.

Viewed fromanother'angla'itis. an object of my invention to provide-a regenerative system employing substantially constant main-field winding excitation that .is essentially independent of the supply circuit voltage, but is dependent upon the regenerated current for purposes to be set forth.-

The various novel circuit arrangements may best be understoo by reference to the and connections employed inmy invention Specification oi Letters Patent.

srsrnu or common Patented June 15,1920.

accompanying drawings, in which Figures 7 1916, Serial No. 127,381. Divided and this application filed October S 1c, 1918. Serial no. 258443,.

a chart, of wel -kn own form, indicating the sequence of operation of the various motorcontroll ng switches shown in Fig. 2; and Fig. 4 1s a diagrammatic view of an auxillary control system for operating the system of Fig. in accordance with the chart,

, ike reference characters designate like parts In all of the figures.

Referrmg to Fig. 1 of the drawin s, the system hereshown comprises a supp y circult that includes a supply conductor marked Trolley and a return circuit conductor marked Ground; a dynamo-electrio machine, such as a direct-currentrailway motor, for example, having an armature A and a series-type field winding F;

and an auxiliarhmotor-generator set compris ng a motor that is supplied with propelhng energy from a: suitable source, such as a battery B, anda enerator or exciter G, that 1s suitably mec anically connected to the motor M, as by a shaft S.

The motor M is provided with a shunt field magnet winding 1, the strength of which may be varied by a suitable resistor 2, and a series-type field winding 3, that is connected 1n series-circuit relation with the armature The generator Gr has a shunt field'w-mding 4 and a variable resistor 5,and

is connected to energize the field windingiF of the propelling motor, thereby imparting a compounding characteristic] thereto durmg regeneratlon. A series-typefield winding 6 for the generator G is also connected inseries relation with the main armature A,and is suitably difierentially-woundfwith respect to the shunt field winding 4, thus act- 1n 1n. opposition thereto.

n Fig. 1, the circuits of'the motor Maud the generator G are interconnected and a.

reversing switch BS is conveniently intersed between the armature A and the circuits that include the field'windin F and the entire motor-generator set.. T e series field winding 3 of- ,the motor M may be wholly or partially short-circuited by one or more sw1tches 7. for purposes of control.

The general operation of the system of Fig. 1 is as follows: During motor acceleration, the current traverses the s stem as indicated b the solid arrows, an the reversing switc RS occupies the solid line position. For regenerative operation, the elecsupply circuit, the operation of thesystem,

.- chine field winding F, is correspondin''glLy current.

' erator set, also serves to decrease the e ecative to compensation for, su ply-circuit voltage fluctuations, may be p escribed as follows: If the supply-circuit voltage decreases, the regenerated current will corre spondingl increase'because of the relatively reat difl erence between the momentumriven machine volta e and the volta e of the supply circuit. he field flux o the shunt motor M will, "consequently, be

strengthened through the increased energization of the series field winding 3, there i d of the motor-genf-I' erator set, in accor ance with well-lmow-n. principles. The output of the J mentors,

by decreasing the s that is to say, the excitation oft e m m decreased, thereby tending to maintain, a substantiall constant value o f. regenerated ufrthermore, the temporary increase of regenerated current, in addition to the slowing-down efiect on the motorentive field flux of the generator G by reason a of the differential action of the series and shunt, field windin s thereof. The excitation of the series eld winding F is thus again decreased, with the desired effect of maintaining a substantially constant regenerated current. .Modifications of the system illustrated, by omitting certain of the field windings of the motor-generator set, may be employed in some instances, dependent upon operating conditions.

Fig. 2 illustrates a system that is adapted for field control and regenerative control,

and is dependent upon the differential action between a battery and a small exciter that is driven by a motor. The system comprises a suitable supply circuit as previously described; the armature' A: series field winding F; a motor-generator set similar to that shown in Fig. 1; a main circuit resistor, the sections of which are adapted to res ectively short-circuited by switches R1,

2 and R3; line switch LS; the switch 7 for short-circuiting the series field windingB; a' switch 9 for short-circuitin a rtion of the series field winding 6 {an a p urality of .zero field excitation.

switches G1 and G2 for short-circuitin sections of the auxiliary generator field-c rcuit resistor 5.

Assuming that the motor-generator set 0 erates at a substantiall constant speed, t e relative voltages of t e battery and the motor-generator set ma for instance, be chosen in such manner t at, when the shunt field winding 4 of the generator G is alone active, that is to say, with no load on the main motor, the voltage ofthe generator armature is equal and opposite to the battery voltage, and, therefore, the main motor has However, when the main motor is operative and is consuming current from the suppl circuit, the generator series field winding .6 is designed to oppose or counteract the shunt field winding 4, thereby decreasing the generator voltage to a value that is lessthan the voltage of the battery, whereupon the battery Wlll energize the main series field windin F, the energization varying directly wet the main motor load.

If desirable, the shunt and series field windings of the small motor M may be differentially wound to cause an increased motor speed with increased main motor load, thus changing the operating characteristics-of the main motor, as will be understood.

As indicated by the sequence chart of Fig. 3,3and in the auxiliary control system of av familiar type that is-illustrated in Fig. 4, the main motor is accelerated by initially Fig. 4.

eferring now to Fig. 5, the system shown comprises the suppl -circuit conductors respectively marked rolley and Ground, the main motor armature A and field winding F, an auxiliar motor-generator set including a motor and a generator G, a battery 13, and a main circuit acceleratin resistor R. The motor M is supplied wit energy from the battery B and is provided with a variable shunt field winding 1, and a second fieldwinding 24 that is connected in series circuit with a variable resistor 25 across the main field winding F. The gen eratorG has its armature connected to excite the field winding F, and is provided with a variable field winding 26, which is series circuit with the main armature A.

The regenerative operation of the s stem may be briefly described as follows: 'egulation of the regenerated current may be effected by suitable manipulation of the resistor R or the resistor 25 to vary the field current of the generator (it or of the motor M, respectively, or by variation of the current in the field winding 1 or the field winding 26,'as will be understood. For a given direction of rotation of the main motor, the

excitation of the field winding 24 will re-.

main constant in direction, by reason of its association with the main field winding F, and thus cannot have a negative compounding effect upon the small motor, to cause an undesirably high speed thereof.

I do not wish to be restricted to the specific circuit connections or arrangement of parts herein set forth, as various modifications thereof may be effected without departing from the spirit and scope of my invention.

I desire, therefore, that only such limitations shall be imposed as are indicated in the appended claims.

I claim as'my invention:

1. In a system of control, the combination with a supply circuit and a main dynamoelectric machine having an armature and a field winding, of a plurality of auxiliary mechanically-connected armature windings respectively acting as driving means and as an exciter for said main field winding, and an energy-accumulating device connected in series circuit relation with said main armature and field winding between the supply circuit conductors and adapted to energize said driving armature, the latter having field windings respectively energized by the device and the main-machine current.

2. In a system of control, the combination with a supply circuit and a main dynamo-electric machine having an armature and a field winding, of a plurality of auxiliary mechanically-connected armature wind' ings respectively acting as driving means and as an exciter for said main field winding, and means connected in series-circuit relation with the main armature and held winding between the supply-circuit conductors for su l in ener to said drivin armaiii; la er hai ding field windi ngsrespectively energized by the last-named means and the main-mac ine current.

3. In a system of regenerative control the combination with a supply circuit and a main dynamo-electric machinehaaring an armature and a field windin of a plurality of auxiliary mechanica ly-connected armature windings respectively acting as drivin means and as an exciter for said main eld winding, low-voltagc means connected in series relation with the main armature between the supply-circuit conductors for supplying energy to said driving armature, and means for causing the exciter voltage to vary in the opposing direction to changes of regenerated current.

4. In a system of control, the combination with a supply circuit, and a momentumdriven armature of a dynamo-electric machine having a series field-magnet windings, of an auxiliary generating dynamo-electric machine connected to energize said field winding, an inde endent source of energy, a driving motor or said auxiliary machine receivin energy from said source and having a eld-magnet winding connected in parallel-circuit relation with said series eld winding, and means for varying the amount of energy delivered to the series field winding from the auxiliary machine to vary the regenerated current.

5. In a system of control, the combination-with a supply circuit and a main dynamo-electric machine having an armature and a field winding, of a plurality of auxiliary mechanically-connected armature windings respectively acting as driving means and as an exciter for said main field winding, and a plurality of field windings for the auxiliary armatures respectively ener ized in accordance with the main-field win ing voltage and the main-armature cur rent.

6. In a system of control, the combina" tion with a supply circuit and 'a main dynamo-electric machine having an armature and a field winding, of a plurality of auxiliary mechanically-connected armature windings respectively acting as driving means and as an exciter for said main field winding, an energy-accumulating device connected in series relation with the main armature for supplying energy to said driving armature, field windings for the respective auxiliary varmatures energized from said device, and other field windings for the auxiliary armatures respectively energized in accordance with the main-field-winding voltage and the main-armature current.

In testimony whereof, I have hereunto subscribed my name this 30th day of Sept.,

, RUDOLF E. HELLMUND. 

